ผลของการเพิ่มแสงคั่นช่วงกลางคืน อัตราปุ๋ย และการขาดธาตุอาหารต่อการเจริญเติบโตของคัตเตอร์ (Symphyotrichum ericoides)

Abstract

The effects of night break, fertilizer rates and nutrient deficiency on growth and development of Cutter (Symphyotrichum ericoides). The research was conducted from December in 2020 to March in 2021 in 2 experiments. Experiment 1: Effect of night-break and fertilizer rates on growth and development of Cutter were studied. This research aimed to study the effects of night-break and fertilizer rates on growth and development of Cutter. Plant was grown under plastics greenhouse with temperature of 27±2 °C, 70 % relative humidity (RH), and the average midday light intensity was 836.0 µmol m-2 s-1. The experimental design was (3×4) +1 factorial treatments in completely randomized design (CRD). Three levels of night-break (2, 3 and 4 hours) and four levels of fertilizer rates (0, 1.5, 3.0 and 4.5 g pot-1) were supplied and compared with control treatment (not receiving night-break and fertilizer). At 8 weeks after planting (WAP), the result found that there had no flowering in control treatment. Plants supplied with night break 3 and 4 hours combination with 1.5 g fertilizer gave the highest of plant height. Moreover, using night break 4 hours combined with fertilizer rate 1.5 g pot-1 gave the greatest in flower quality, such as inflorescence length and number of florets per peduncle, inflorescence fresh and dry weight of Cutter

Experiment 2: Studied on the effect of nutrient deficiency on growth and development of Cutter. This research aimed to study the effect of nutrient deficiencies on growth and development of Cutter. The Cutter was grown in hydroponics using double pot system during December in 2020 to March in 2021. The experimental design was Completely Randomizes Design (CRD) with 8 treatments i.e., T1) plant were supplied with Hoagland and Arnon (1950) nutrient solution (control treatment), T2 to T7 plant were supplied with -N, -P, -K, -Ca, -Mg and -Fe, respectively and T8 plant were grown in deionized water (DI water). All deficiency treatments were supplied with same amount of other essential nutrient. The result showed that at 4 weeks after planting (WAP), yellowing were appeared throughout the entire leaf (interveinal chlorosis) when supplied with -Fe treatment. At 8 WAP, the average of plant height in -Ca treatment was the lowest. Plants were showed the yellow leaves with the lowest of leaf greenness in -N treatment when comparing to the other treatment except DI water treatment. While photosynthesis rate in -P treatment was the lowest (0.31 µmol m-2 s-1). Flower quality, such as inflorescence length and number of peduncles per plant were less than other treatments except DI water treatment.