Crp Res. 46 (1, 2 & 3) : 169-173 (2013) With fur figures Printed in India Effect f nitrgen rate and fungicide r cmpst tea applicatin n tuber yield and quality f ptat cultivars SAMUEL Y. C. ESSAH*, R. D. DAVIDSON AND A. HOUSER Department f Hrticulture and Landscape Architecture Clrad State University, San Luis Valley Research Center 0249 East Rad 9 Nrth Center, Clrad, 81125, USA *(e-mail : sessah@lamar.clstate.edu) (Received : August 2013) ABSTRACT The envirnmental impact f using chemical fungicides t suppress disease in ptat prductin is becming a cncern in recent years. The use f cmpst tea as a disease suppressant is becming ppular. A study was cnducted at Clrad State University, San Luis Valley Research Center, U. S. A. frm 2007 t 2009, t evaluate the interactive effect f nitrgen fertilizer rate and cmpst tea r fungicide applicatin n tuber yield, tuber size distributin and quality f ptat cultivars Russet Nrktah and Russet Nugget. Treatment cmbinatins included nitrgen fertilizer (N) applied at 90 and 134 kg/ha with cmpst tea r fungicide applied. Tw cntrl treatments were established where N was applied at 90 and 134 kg/ha with n cmpst tea r fungicide applicatin. Medium size tuber yield (114-284 g tubers) increased significantly in all three years fr Russet Nrktah when cmpst tea was applied with 90 kg N/ha (2007) r with 134 kg N/ha (2007, 2008 and 2009). Marketable size tuber yield (114-454 g tubers) f Russet Nrktah was significantly increased when cmpst tea was applied with 134 kg N/ha (2007 and 2009), cmpared t the cntrl treatment. r Russet Nugget, medium size tuber yield increased significantly in all three years f the study when cmpst tea was applied with 90 kg nitrgen fertilizer/ha, cmpared t the cntrl treatment. The yield f large marketable size (170-340 g and 170-454 g tubers) increased when cmpst tea was applied with 90 kg N/ha in tw f the three years study. r Russet Nrktah, the applicatin f fungicide increased tuber specific gravity, cmpared t the applicatin f cmpst tea and the cntrl treatments. Hwever, fr Russet Nugget tuber specific gravity was similar in the fungicide and cmpst tea treatments in tw f the three years study. Results f these studies suggest that cmpst tea can be used with reduced r n fungicide applicatin t prduce ptimum tuber yields in ptat prductin. Key wrds : Cmpst tea, fungicide applicatin, nitrgen rate, ptat tuber yield, tuber specific gravity INTRODUCTION One f the diseases in ptat that ften cause yield reductin is early blight, caused by Alternaria slani. Early blight is influenced by sil fertility and plant nutritin. Barclay et al. (1973) and Davis (1985) stated that high rates f nitrgen (N) fertilizer culd suppress early blight. Hwever, the rates f N needed t suppress early blight are higher than the ptimum N needed fr maximum tuber yield (Barclay et al., 1973). Ecnmic cntrl f early blight has been achieved by applying ptimum N rates fr maximum tuber prductin and using fungicides t cntrl early blight (Mackenzie, 1981; Sltanpur and Harrisn, 1974). The use f fungicide prgrammes in ptat prductin has raised sme cncerns in recent years due t its negative envirnmental impact. A nn-chemical prduct that can suppress fliar disease and result in equal yields r yields that are higher than thse btained when fungicides are used will reduce envirnmental cncerns. Cmpst tea is a liquid slutin frm cmpst that cntains plant nutrients. The cncept f using cmpst tea in crp prductin is relatively new and few research has been cnducted t dcument the effectiveness f
170 Essah, Davidsn and Huser cmpst tea in ptat prductin. Hibar et al. (2006) and Haggag and Saber (2007) in their studies reprted that cmpst tea suppressed disease. Undcumented surces have suggested that cmpst tea increases the micrbial activity in the sil. Hibar et al. (2006) in their study shwed that cmpst tea culd stimulate rt and vegetative grwth, while Haggag and Sabar (2007) bserved that cmpst tea increased crp yield and quality. The bjective f this study was t evaluate the interactive effect f nitrgen fertilizer rate (lw and ptimum) and cmpst tea r fungicide applicatin, n ptat tuber yield, tuber size distributin and quality. MATERIALS AND METHODS The field experiments were cnducted at the San Luis Valley Research Center, Clrad State University, USA frm 2007 t 2009 in a tw years rtatin system during the summer grwing seasns. The previus crp befre the 2007 and 2009 ptat crp was barley (Hrdeum vulgare L.), and the previus crp befre the 2008 ptat crp was sudan grass (Srghum sudanense). The experiment was established as a factrial arrangement f the treatments in a randmized cmplete blck design. Each treatment was replicated fur times. Treatments included cmpst tea applied at a rate f 75 l/ha with 90 and 134 kg nitrgen fertilizer/ha, and fungicide applied with 90 and 134 kg nitrgen fertilizer/ha. The fungicide prgramme used was the applicatin f brav at 1.7 l/ha, quadris at 0.5 l/ha and dithane at the rate f 2.3 kg/ha. The three fungicide chemistries were applied at 10 days interval. Tw ptat cultivars Russet Nrktah and Russet Nugget were used as test crps. Seed pieces were planted with an experimental ptat planter n May 11, 2007, May 6, 2008 and May 14, 2009. Ptat seed was planted in ridges with in-rw seed spacing f 30 cm. Individual plts cnsisted f fur rws f ptat, each measuring 7.6 m length. Thrughut the grwing seasn, plt care and cultural management practices fllwed recmmendatins by Clrad State University fr the tw cultivars studied. On September 4, 2007; August 29, 2008 and September 8, 2009, ptat vines were killed using a mechanical vine beater. Tubers frm each experimental plt were harvested using an experimental ptat harvester frm the middle tw rws n September 25, 2007; September 25, 2008 and September 23, 2009. Tubers harvested frm each plt were weighed t recrd ttal field yield. Tubers were srted int varius size distributin grups based n weight (114-454, 114-284, 170-341 and 170-454 g). Tuber specific gravity was measured using the weight-in-air/weight-inwater methd. Statistical analysis was cnducted using analysis f variance [ANOVA (SAS versin 9.2; SAS Institute, Cary, NC)]. Where apprpriate, differences amng treatment means were cmpared using isher s prtected least significant difference (LSD) test at the 0.05 level f prbability. RESULTS AND DISCUSSION Tuber Yield and Tuber Size Distributin Russet Nrktah The yield f medium size (114-284 g) tubers increased significantly when cmpst tea r fungicide was applied in the ptimum nitrgen rate (134 kg N/ha) plts (ig. 1a-c). In tw f the three years (2007 and 2008), medium size tuber yield was similar fr cmpst tea and fungicide applied treatments at 134 kg N/ha rate (ig. 1a and b). In 2009, cmpst tea applicatin in ptimum N rate (134 kg N/ha) plts resulted in yields that were significantly higher than the fungicide applied and cntrl treatments (ig. 1c). At the lwer N rate f 90 kg N/ha, cmpst tea applicatin utyielded the fungicide applied and cntrl treatments in 2007 (ig. 1a), but nt in 2008 r 2009. The yield increase bserved when cmpst tea was applied in the ptimum N rate plts was, 12, 7 and 6% in 2007, 2008 and 2009, respectively (ig. 1a-c). Crrespnding yield increase fr fungicide applicatin was 14 and 5% in 2007 and 2008, respectively (ig. 1a and b). In 2009, the yield bserved in fungicide applied plts with ptimum N fertilizer applicatin was similar t yield frm the cntrl plts and was significantly lwer than yield frm the cmpst tea treatment. Marketable tuber yield (114-454 g) was increased with the applicatin f cmpst tea r fungicide in the ptimum N applied plts in tw f the three years study (2007 and 2009) (ig. 2a and c). Cmpst tea increased
Respnse f ptat t cmpsttea andfungicide applicatin 171 ^ 24.5 E 23.s ;r 22.5 zr.s 3 20.5 I rg.s s L {t J 32 30 28 26 24 e 4a G'40 Et 39 =3s 37 36 35 P34 33 32 a (20071 Nitrgen Rate {kg/ha) 134..,.(..Cntrl..1-CmpstTea -9 ungicide -.-r<-.- Cntl (2008) 90 a34 i.rgen taie (kg/ha) +Cmp$'fea Nitrgen Rate {kg/ha}.,.-j4,.cntrl --l-cmpsttea - ungicide -e lngidde c (2009) ig. 1. Interactive effect f nitrgen rate and cmpst medium size (114-284 g) tubers f Russet Nrktah (ig. 1a-c) 2OO7-09. marketable tuber yield by 7 and 60/, and the use f fungicide prgrammes increased marketable tuber yield by 18 and 4h in 2OO7 and2oo9, respectively (ig. 2a and c). It shuld be nted that in 2008, marketable tuber yield was similar fr all three treatments at 134 kg N/ha applicatin rate (ig. 2b). Harrisn et al (1965) and Harrisn and Venette (1970) stated that the infestatins f early blight pathgen n fliage did nt always result in yield lss, and ccasinally chemical cntrl did nt imprve yield (Eastn et al., L9751" The yield increases bserved in the applicatin f cmpst tea r fungicide prgrammes agree with the findings f Mackenzie (L981) and Sltanpur and Harrisn (19741, wh cncluded that ecnmic cntrl f early blight was achieved by using ptimum N rates fr maximum tuber prductin and using fungicides t cntrl early blight. Results f this study clearly demnstrate that fr Russet Nrktah, cmpst tea can be applied t increase ptat G tr) = {J = re {, :' 1-5 4a- = 90 131 I g Nitrgerr Rare (kg/ha) d) 35 30 25 J..'iti.. Cntrl -t3- ungicicle 46 26..'.{r.'Cntrl -#CnrpstTea - t ungicicle ig. 2. Intera"ti,," "n""? [?:?,?)"*"" rate and cmpst tea r fungicide applicatin n marketable size (114-454 g) tuber yield f Russet Nrktah (ig. 2a-c) 2OO7-O9. tuber yield when N is applied at the ptimum rate recmmended fr Russet Nrktah. Russet Nugget s0 134 Nitrgen Rare {kglha) a(20071 +Cmpst Tea 90 134 Nitrgen Rate {kg/ha}...x... Cntrl -+CmpstTea - G-' ungicicle b (2008) In tw f three years (2008 and 2009), the yield f medium size tubers was higher when cmpst tea was applied in the lw N applied plts (90 kg N/ha) (ig. 3b and c). ungicide applicatin prduced similar yield t the cntrl treatment at the lw N applicatin rate in 2008 and 2009, but these yields were lwer than the cmpst tea yields. The yield increase bserved fr cmpst tea at the lw N applicatin rate was 13 and ll/, respectively, in 2008 and2oo9, when cmpared t the cntrl treatment (ig. 3b and c). In2O07, medium size tuber yield was similar fr
172 Essah, Davidsn and Huser a (2007) a (170-340 g) tubers 2007 b (2008) c (2009) ig. 3. Interactive effect f nitrgen rate and cmpst medium size (114-284 g) tubers f Russet Nugget (ig. 3a-c) 2007-09. cmpst tea and fungicide applied treatments, and these were higher than the cntrl treatment (ig. 3a). At the ptimum N rate f 134 kg N/ha, cmpst tea increased medium size tuber yield by 14 and 20% in 2007 and 2008, respectively (ig. 3a and b). ungicide applicatin at ptimum N rate f 134 kg N/ha increased medium size tuber yield by 33 and 9% in 2007 and 2009, respectively. The yield f large marketable size tubers (170-340 g) was evaluated fr Russet Nugget. Cmpst tea and fungicide applicatin increased the yield f 170-340 g tubers by 36 b (170-454 g) tubers 2008 ig. 4. Interactive effect f nitrgen rate and cmpst marketable size tubers f Russet Nugget (a and b) 2007-08. and 80%, respectively, at the ptimum N rate, in 2007 (ig. 4a). In the 170-340 g tuber size grup, yields were lwer and similar fr all three treatments at the lw N rate f 90 kg N/ha. In 2008, cmpst tea increased the yield f 170-454 g tuber size by 18% in the lw N rate plts (ig. 4b). N significant yield increase was bserved in 2009 (data nt shwn). The yield results fr Russet Nugget indicate that cmpst tea can be applied at lw N rates (90 kg N/ha) t prduce similar r higher yield than when fungicide prgrammes are used as disease suppressant. Tuber Specific Gravity The effect f cmpst tea and fungicide applicatin n tuber specific gravity f Russet Nrktah and Russet Nugget was evaluated ver the average f the tw nitrgen applicatin rates used in this study. r Russet Nrktah,
Respnse f ptat t cmpst tea and fungicide applicatin 173 Table 1. Effect f fungicide and cmpst tea applicatin averaged ver nitrgen applicatin rate n ptat tuber specific gravity Treatment Russet Nrktah Russet Nugget 2007 2008 2009 2007 2008 2009 Cntrl* 1.080c 1.075ab 1.083b 1.089b 1.097b 1.11a Cmpst tea 1.082b 1.074b 1.083b 1.088b 1.100a 1.10a ungicide 1.084a 1.076a 1.085a 1.091a 1.100a 1.11a *Cntrl Nitrgen fertilizer with n cmpst tea r fungicide applicatin. igures in the same clumn and bearing the same letters are nt significantly different frm each ther at P=0.05 level. fungicide applicatin increased tuber specific gravity in tw f the three years (2007 and 2009) (Table 1). Cmpst tea applicatin increased tuber specific gravity in 2007, when cmpared t the cntrl, but tuber specific gravity in the cmpst tea applied treatments was similar t the cntrl in the ther tw years (Table 1). r Russet Nugget, the applicatin f fungicide increased tuber specific gravity, and the gravities were higher than tubers frm the cntrl and cmpst tea treatments in 2007, but higher than the cntrl treatment in 2008 (Table 1). N significant difference was bserved in tuber specific gravity amng the treatments in 2009. In general, the data suggest that the applicatin f fungicide in ptat prductin increases tuber specific gravity when cmpared t the applicatin f cmpst tea, even thugh in sme years, cmpst tea can prduce tubers with similar specific gravities t fungicide applied plts. CONCLUSION The main purpse f this study was t evaluate the interactive effect f nitrgen applicatin rate (lw and ptimum rates) and cmpst tea r fungicide applicatin in ptat prductin, and t determine whether cmpst tea culd be used as an alternative t fungicide applicatin t btain ptimum ptat tuber yield. Results btained in the three years study clearly demnstrate that in Russet Nrktah, cmpst tea can be used as an alternative t fungicide applicatin at ptimum nitrgen fertilizer rates t prduce higher r similar medium and marketable size tuber yields. In Russet Nugget, cmpst tea applicatin can increase tuber yield at lw nitrgen fertilizer rates, cmpared t the use f fungicide as fliar disease suppressant. REERENCES Barclay, G. M., Murphy, H. J., Manzer,. E. and Hutchinsn,. E. (1973). Effects f differential rates f nitrgen and phsphrus n early blight in ptates. Am. Ptat J. 50 : 42-48. Davis, J. R. (1985). Appraches t cntrl ptat early dying caused by Verticillium dahlia. Am. Ptat J. 62 : 177-85. Eastn G. D., Nagle, M. E. and Bailey, D. L. (1975). Lack f fliar prtectin frm early blight Byaircraft applied fungicides n sprinkler irrigated ptates. Plant Dis. Rep. 59 : 910-14. Haggag, W. M. and Saber, M. S. M. (2007). Suppressin f early blight n tmat and purple blight n nin by fliar sprays f aerated and nn-aerated cmpst teas. J. d, Agric. and Envirn. 5 : 302-09. Harrisn, M. D., Livingstn, C. H. and Oshima, N. (1965). Epidemilgy f ptat early blight in Clrad. 1. Initial infectin, disease develpment and the influence f envirnmental factrs. Am. Ptat J. 42 : 279-91. Harrisn, M. D. and Venette, J. R. (1970). Chemical cntrl f ptat early blight and its effect n ptat yield. Am. Ptat J. 47 : 81-86. Hibar, K., Daami-Remadi, M., Jabnun- Khiareddine, H., Znaidi, I. E. and El- Mahjub, M. (2006). Effect f cmpst tea n mycelial grwth and disease severity f usarium xysprum f. sp. Radices lycpersici. Bitechnl. Agrn. Sc. and Envirn. 10 : 101-08. Mackenzie, D. R. (1981). Assciatin f ptat early blight, nitrgen fertilizer rate and ptat yield. Plant Dis. 65 : 575-77. Sltanpur, P. N. and Harrisn, M. D. (1974). Interrelatins between nitrgen and phsphrus fertilizatin and early blight cntrl f ptates. Am. Ptat J. 51 : 1-7.