Kandungan Pigmen Fotosintetik dan Pertumbuhan Vegetatif Tanaman Kedelai (Glycine max L. Merr.) var. Grobogan Pada Tingkat Ketersediaan Air yang Berbeda

Abstract

Kedelai merupakan sumber protein yang murah sehingga permintaan tinggi, tetapi produksi kedelai di Indonesia rendah. Tanaman kedelai umumnya ditanam di sawah tadah hujan sehingga rawan cekaman kekeringan dan menyebabkan produksi rendah. Penelitian ini menggunakan metode ekperimental,  bertujuan mengkaji pengaruh tingkat ketersediaan air terhadap kandungan pigmen fotosintetik daun dan pertumbuhan vegetatif tanaman kedelai [Glycine max (l.) Merr.] varietas Grobogan. Penelitian dilakukan di kebun percobaan dan laboratorium Struktur dan fungsi tumbuhan  Departemen biologi FSM UNDIP, menggunakan Rancangan Acak Lengkap (RAL) satu faktor berupa tingkat ketersediaan air yang berbeda yaitu 100%, 75%, 50%, dan 25% kapasitas lapang.  Data dianalisis dengan analisis sidik ragam One Way ANOVA, dilanjutkan dengan Uji DMRT dengan tingkat kepercayaan 95%. Hasil penelitian menunjukkan bahwa penurunan persentase ketersediaan air tidak memengaruhi kandungan pigmen fotosintetik daun kedelai. Penurunan persentase ketersediaan air menurunkan pertumbuhan tajuk, untuk jumlah daun mulai turun pada ketersediaan air 25%, tinggi tanaman pada 75%, bobot tajuk pada 50%. Ketersediaan air paling optimal bagi panjang akar dan bobot akar adalah 75%.  Soybeans are a cheap source of protein, so demand is high, but soybean production in Indonesia is low. Soybean crops are generally planted in rainfed rice fields, so they are prone to drought stress and cause low production. This study used an experimental method, aimed to examine the effect of water availability on the photosynthetic pigment content of leaves and vegetative growth of soybean plants [Glycine max (l.) Merr.] Grobogan variety. The research was conducted in the experimental garden and laboratory Plant structure and function of the Department of Biology FSM UNDIP, using a one-factor Complete Randomized Design (RAL) in the form of different levels of water availability, namely 100%, 75%, 50%, and 25% field capacity.  The data was analyzed by One Way ANOVA fingerprint analysis, followed by DMRT Test with a confidence level of 95%. The results showed that the decrease in the percentage of water availability did not affect the photosynthetic pigment content of soybean leaves. A decrease in the percentage of water availability decreases the growth of the header, for the number of leaves begins to fall at water availability 25%, plant height at 75%, header weight at 50%. The most optimal water availability for root length and root weight is 75%.