PRODUCTION OF MINERAL NUTRIENT-RICH MULTIPURPOSE PUMPKIN LEAFY VEGETABLESUSING INTEGRATED RESOURCE MANAGEMENT

Abstract

Enhancing mineral nutrient composition in multipurpose pumpkin (Cucurbita moschata Duch.) is important since it contributes to household food security. To respond to this need, an experiment arranged in split-plot in randomized complete block design and replicated three times was conducted at Chuka University for two seasons from January 2019 to July 2020. The main plots were assigned to nitrogen (CAN) (0, 50, 100 and 150 kg N/ha), sub-plots to mulch (no mulch, black-painted and unpainted rice straws), while split-plots to gibberellic acid (GA3) (0 mg/L, 40 mg/L and 80 mg/L). Nitrogen for each rate was applied in two equal doses at three weeks post-emergence and at the beginning of flowering. The black-painted and unpainted rice straws were placed on plots after land preparation. The GA3 solution was sprayed onto plants using a knapsack sprayer, starting with 40 mg/L followed by 80 mg/L, once during the fourth week after emergence. Data collection was done fortnightly from the fourth week after emergence and data values were subjected to analysis of variance using SAS software. Means were separated using the least significant difference test at α=0.05. Highest levels of potassium and magnesium were obtained for 100 kg N/ha. On the other hand, phosphorus and beta-carotene were highest in treatments where unpainted rice straw mulch was used, while application of 80 mg/L of GA3 gave high phosphorus and potassium contents. Results further showed that combined N fertilizer, mulch and GA3 had a significant (P<0.05) effect on nitrogen, phosphorus, potassium, magnesium and beta-carotene contents during both seasons, implying that they are useful factors in evaluation of mineral nutrient contents in leaves of multi-purpose pumpkins.