Two local cassava (manihot esculenta crantz) varieties on the resilience in drought stress

Climate change is an escalating global challenge that threatens food security and agricultural livelihoods. Unpredictable climate phenomenon has happened in around the globe in recent years. In the tropical region, including Indonesia, between rainy and dry season has become uncertain. And, the distribution of raining is uneven. Consequently, some region has resulted in the limiting supply of water, such as in a couple part of Central Java, causing dryness. In the face of this phenomenon, cassava emerges as a promising crop with inherent resilience and adaptability. Cassava has been a staple food for millions, particularly in tropical regions. Its deep root system enables access to subsurface moisture during droughts, and its sturdy leaves and stems resist the impacts of extreme weather events and pest invasions. This paper studied the growth response of cassava seedlings at drought stress levels and cassava varieties. The experimental design used was a completely randomized design arranged in factorial (4x2) with 3 replications. The first treatment was drought stress (0%, 25%, 50%, 75%) and the second treatment was cassava varieties (Ketan, Mentega). CI-340 Handheld Photosynthesis System was used to analyse net photosynthetic rate. The results demonstrated that the level of drought stress decreased the net photosynthetic rate, leaf area, root fresh weight, dry root weight but increased root length. Dryness of 75% resulted in 45.06 cm of length root. Cassava variety grown on an extreme drought (75% dry) produced lower leaf area (50 cm2). Stem diameter was bigger on Ketan variety (20.56 mm) compared to Mentega variety (19.54 mm). Number of roots of Ketan variety (42.36) was greater than Mentega variety (24.08). Fresh root weight and dry root weight were correlated with the level of dryness. The drier of media was the lower of root weight, with the result of 8 g for fresh weight and 3 g for dry weight. In conclusion, Ketan variety is more resilient than Mentega variety.