Assessment of growth, photosynthetic and biomass characteristics of selected fodder grass varieties under standardized water regimes

Abstract

Fodder grasses are vital for global livestock and sustainable agriculture, but lack of understanding of their specific water needs to optimize photosynthesis, biomass, and overall growth. This gap was investigated by comparing three fodder grass species CO3, CO4 and Super Napier (SN) under controlled, standardized water conditions (10 liters/day) within protected environments. Data was gathered at 3 – 6 weeks after planting (WAP). Fodder varieties were insignificant in plant height, leaf production rate (LPR) and leaf width. But all the varieties experienced a sharp decline in LPR at 4WAP before rebounding in subsequent weeks. Leaf length and tillers/plant were significant where CO3 exhibited highest leaf length (120cm). SN displayed significantly fewer tillers (9 at 6WAP). Photosynthetic efficiency, as measured by quantum yield and chlorophyll content, remained high and insignificant across varieties at 6WAP, suggesting similar light-harvesting capacities. Stomatal conductance was insignificant across varieties but lower values observed at 4WAP. Biomass performances at 3WAP, CO3 had the highest fresh weight (189.6g), significantly more than CO4 (146.7 g) and SN (84.7 g) while CO3 and CO4 were insignificant in dry weight, but SN's dry weight (36.4 g) was significantly lower. At 6 WAP, the fresh weights of CO3 and CO4 were insignificant. However, SN's fresh weight (1198 g) was significantly lower than CO3 and CO4. At 6 WAP, dry weight differed significantly (p = 0.043), with CO3 having the highest (613.7g). Overall, CO3 and CO4 generally out yielded Super Napier in both fresh and dry biomass at 6 WAP. The results can inform the development of more efficient cultivation practices and enhance the resilience and productivity of fodder systems, particularly for high-yielding varieties like CO3 and CO4, in water-limited regions.