Iklim yang tidak menentu dan tanah yang tidak subur merupakan faktor penyebab fluktuatifnya hasil panen. Selain itu, pemberian pupuk yang tidak tepat menyebabkan tanaman kangkung darat tidak dapat menyerap nutrisi secara optimal. Aplikasi asam humat sebagai biostimulan dapat digunakan untuk memperbaiki struktur tanah dan mengoptimalkan produktivitas tanaman. Penelitian ini bertujuan untuk mempelajari pengaruh aplikasi asam humat terhadap pertumbuhan, produktivitas, dan serapan nitrogen pada tanaman kangkung darat. Penelitian dilakukan dengan Rancangan Acak Lengkap (RAL) dengan faktor tunggal yang meliputi 7 perlakuan yaitu kontrol, pemberian asam humat melalui daun dengan dosis 5 mg/L, 20 mg/L, dan 35 mg/L, dan melalui akar dengan dosis 5 mg/L, 20 mg/L, dan 35 mg/L. Media tanam berupa tanah tanpa penambahan pupuk dasar untuk melihat hasil paling optimal dari pengaruh pemberian asam humat. Hasil penelitian menunjukkan bahwa pemberian asam humat dosis 20 mg/L melalui daun maupun akar menyebabkan peningkatan tinggi tajuk, diameter batang, jumlah daun, biomassa dan serapan nitrogen tanaman kangkung darat. Kadar klorofil tertinggi tanaman kangkung diperoleh pada perlakuan asam humat melalui daun pada dosis 35 mg/L. Berdasarkan penelitian dapat disimpulkan bahwa pemberian asam humat melalui daun dan akar dapat meningkatkan pertumbuhan, produktivitas, dan serapan N pada tanaman kangkung darat.

No abstract

Watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai) is a horticultural plant that belongs to the Cucurbitaceae family with high public demand, however, local markets sometimes have limited supply. The existence of watermelon varieties that are not pest-resistant causes its production to be erratic. Therefore, plant breeding efforts are required to produce superior varieties through the stability test of plant characters. For watermelon to be certified as a new variety, it needs to possess a stable and adaptive character to various conditions. The F1 watermelon from crossing ♀ ‘Putri Delima’ with ♂ ‘Maduri’ produces inole-shaped fruit, red flesh, and a sweet taste. Therefore, this study aims to determine the stability of the phenotypic character of watermelon F2 from crossing ♀ ‘Maduri’ with cultivar ♂ ‘Putri Delima’ and was conducted in Jamusan, Bokoharjo, Prambanan, Sleman, D.I.Yogyakarta fields from August to December. There are five samples of ripe watermelons that were selected randomly while their phenotypic characters were observed qualitatively and quantitatively. Each F2 watermelon character was compared to F1, and the quantitative analysis was conducted using one-factor ANOVA with a confidence level of 5%. The results of quantitative character analysis between F2 and F1 showed a P (P-value)> 0.05. Meanwhile, the results of qualitative observations of F2 watermelon showed different flesh and skin color, while the harvest time from F1 was caused by the segregation of heterozygous crosses. Therefore, it is necessary to select superior phenotypic characters as desired for the next breeding.