Effect of Bed-Top Width, Fertigation and Crop Geometry on Green Pod Yield and Economics of Pole Type French Bean Grown in Poly-Nethouse

A field experiment was conducted under protected poly-net house conditions at the Vegetable Research Farm, Punjab Agricultural University, Ludhiana during September 2021 and January 2022 to study the effect of bed-top width, fertigation levels and crop geometry on growth, yield and economics of pole type French bean (Phaseolus vulgaris L.). The experiment was laid out in a split plot design with three bed-top widths (105, 75 and 37.5 cm, each with 30 cm furrow), five fertigation levels (0, 60, 80, 100 and 120% recommended NPK) and two intra-row spacings (30 and 45 cm), replicated thrice. Results revealed that fertigation levels significantly influenced phenological traits, growth and yield attributes. Higher fertigation levels (100-120% NPK) increased dry haulm weight, pod length, pod weight, pod width, number of pods plant^-1 and green pod yield, whereas 0% NPK induced early flowering and harvesting. Wider intra-row spacing (45 cm) improved yield attributes and green pod yield per plant, whereas closer spacing (30 cm) resulted in higher green pod yield per acre due to increased plant population. Among bed-top widths, 105 cm produced the highest yield per plant, whereas 75 cm bed- top recorded the maximum green pod yield per acre. Economic analysis showed that the combination of 75 cm bed-top width, 120% NPK fertigation and 30 cm intra-row spacing resulted in the highest net returns, whereas the highest benefit-cost ratio was obtained with 75 cm bed-top width, 100% NPK and 30 cm intra-row spacing. Thus, a bed-top width of 75 cm with 30 cm intra-row spacing and 100–120% recommended NPK through drip fertigation is recommended for profitable French bean cultivation under protected conditions.