Drip fertigation with nitrogen and potassium and postharvest susceptibility to bacterial soft rot of bell peppers

Abstract

In 1991 and 1992, drip irrigation was used to apply various rates and timings of nitrogen (N) and potassium (K) to black polyethylene plastic‐mulched bell pepper (Capsicum annuum L.) to determine the effect on fruit quality and susceptibility to postharvest bacterial soft rot (Ervinia carotovora subsp. carotovora). Neither rate nor application timing affected total yield in either year. In 1991, the high fertilizer rate (266–309 kg/ha of N and K, respectively) increased class 1 yield in the first harvest and reduced total discards. In 1992, a year with a colder than average spring, the low fertilizer rate (70–81 kg/ha of NK) increased class 1 yield in the first harvest. Mid‐ or late‐season fertigation produced more second harvest yield and less discards than the first harvest in 1991, but not in 1992. Fruits of plants fertilized with high N and K rates had greater N and dry matter concentration. No differences in color or wall thickness at harvest were detected among treatments. Stored fruits turned red slower with the late season low fertilizer rate. There were no differences in rate of weight loss during storage at 10°C. No differences in progression of bacterial soft rot were detected among treatments in 1991, but the higher fertigation rates or late timing application increased resistance in 1992.

Notes

Partial funding for this research was from Instituto Nacional de Investigacion Agropecuaria of Uruguay (I.N.I.A.), Andes 1365 P.12, Montevideo, Uruguay and from the Unites States Department of Agriculture Special Grant F.L. 89–106: “Agricultural Adjustment in the Southeast Through Alternative Cropping Systems.”; The use of trade names in this publication does not imply endorsement by the North Carolina Agricultural Research Service of the products named, nor criticism of similar ones not mentioned.

Former graduate student, now Researcher, Estacion Experimental Las Brujas, INIA, Ruta 48 ‐km. 10 ‐ Rincon del Colorado C.P. 90.200 ‐ C.C. 33085 Canelones ‐ Uruguay.

Associate Professor

Professor

Associate Professor