Enhancement of Cucumber (Cucumis sativus L.) Growth and Yield under Polyhouse Cultivation Using Biochar-based Growing Substrates

Abstract

Cucumber (Cucumis sativus L.) is an important polyhouse crop, but its productivity depends strongly on the selection of suitable growing substrates that support root growth, nutrient uptake and moisture retention. Biochar-based substrates may improve substrate porosity, water retention and nutrient availability when combined with organic amendments such as FYM. This study aimed to evaluate different combinations of cocopeat, FYM, biochar, vermiculite, vermicompost and sand for improving the growth and yield of cucumber under polyhouse conditions. A field experiment was conducted at the Polyhouse Research Unit, Department of Horticulture, Kumaraguru Institute of Agriculture, Erode, during 2026 to evaluate cucumber (Cucumis sativus L.) growth and yield under polyhouse cultivation using biochar-based growing substrates. The experiment was laid out in a Completely Randomised Design (CRD) with seven treatments and three replications. The treatments comprised T1 - Control; T2 - Cocopeat + FYM (1:1); T3 - Cocopeat + Biochar (3:1); T4 - Cocopeat + FYM + Biochar (2:1:1); T5 - Biochar + Sand + FYM (1:1:1); T6 - Cocopeat + Vermiculite (3:1); and T7 - Cocopeat + Vermicompost (3:1). Growth parameters, including vine length, number of leaves, leaf area index, fresh and dry shoot weight, days to first flowering and fruit set percentage, were recorded. Yield parameters, including number of fruits per plant, individual fruit weight, fruit length, fruit girth and total yield per plant, were also assessed. The results revealed that T4 (Cocopeat + FYM + Biochar at 2:1:1) recorded significantly superior performance in vine length (312.4 cm), number of fruits per plant (35), individual fruit weight (198.3 g) and total yield (6.94 kg/plant) compared with the other treatments. The control (T1) recorded the lowest values for all parameters studied. The beneficial effect of biochar may be attributed to its ability to improve substrate porosity, water retention and nutrient availability, thereby creating a more favourable growing environment for cucumber plants and enhancing their growth and yield. The findings suggest that incorporating biochar at an appropriate level can improve cucumber productivity under protected cultivation.