Dark Green Leaf Color Research Articles

Exploration and identification of morphological characters of local Samosir shallot (Allium ascalonicum L.) accessions for sustainable agriculture

Samosir local shallots are a superior local resource commodity with a very distinctive taste and aroma, more pungent and fragrant, the color is redder and shiny. Currently, Samosir local shallots are experiencing a shortage therefore exploratory research is needed to obtain sources of quality planting material for sustainable agriculture. The objective of the research was to explore and identify the morphological characters of Samosir local shallots accessions at Bakti Raja District. The research method was carried out using a descriptive exploratory method. The results showed that the Samosir local shallots from all the accessions observed had cylindrical leaves with holes, with dark green leaf color, medium leaf size, low leaf density, umbrella-like flower shape, white flower color and purple/white bulb color. There is diversity in the shape of the bulb, namely Siunong-unong Julu accession, Simangulampe 1 and Simangulampe 2 have a globe tuber shape, while Simamora 1 accession has broad elliptic leaf shapes, Simamora 2, Simamora 3, Simamora 4 Marbun Tonga Dolok, Tipang 1 and Tipang 2 has a broad oval shape. Tipang 2 accession had the highest weight of 100 dry shallot bulbs, Simangulampe 1 and Simangulampe 2 accessions had the highest tuber diameter.

Promotion of Improved Onion (Nafis Variety) Production Technology under Irrigated Conditions in Nyangatom District, Low Land Area of South Omo Zone

Onion is an important cash crop that could enhance the income of agro-pastoralists in Nyangatom woreda as the area has huge potential for water availability from the Omo River and fertile land. However, access to improved onion variety is limited in the area. Thus, this study aimed to demonstrate the improved onion variety with its agronomic management in the production season. Onion growers were purposely selected and have taken training on onion production by using recommended doses of fertilizers, pesticides, irrigation, and suitable agronomic practices. Each agro-pastoralist covered 0.064 hectares of land by improved onion. The recorded data from the field experiment and agro-pastoral perceptions were analyzed through simple descriptive and preference ranking tools. From the result of the demonstration trial, the mean bulb yield of the improved onion (Nafis variety) was 125 qt/ha. The average return obtained from the sale of onion bulbs per hectare was 334,925 Ethiopian birr. Moreover, the benefit-to-cost ratio of improved onion production was 8.34:1, which indicates the benefits outweigh the costs, suggesting a positive return on improved onion production in the area. The agro-pastoralist’s preference further showed that the Nafis variety was the best one or superior to the local variety in terms of its high-yielding ability, dark green leaf color, medium bulb size, and market preference. Therefore, the authors suggest the respective government and non-government bodies to further promote improved onion in the area.

Chaya Leaf Infusion (Cnidoscolus aconitifolius) as a Phytogenic for Productivity and Egg Quality of Japanese Quail (Coturnix coturnix japonica) of 17-20 Weeks of age.

Chaya (Cnidoscolus aconitifolius) from family Euphorbiaceae is a plant has leaves similar to papaya leaves but with dark green leaf color. This plant contains phytochemical compounds such as alkaloid, flavonoid, triterpenoids, glycoside, and tannin that can function as antibacterial, antioxidant, and anti-inflammatory. Chaya leaf infusion are processed into infusion before given to the quails through drinking water, this method is used to obtain the phytochemical compounds contained in chaya leaves. This study aimed to evaluate chaya leaf infusion (Cnidoscolus aconitifolius) as a phytogenic source on the productivity and egg quality of japanese laying quail (Coturnix coturnix japonica) aged 17-20 weeks. Chaya leaf infusion is given through drinking water and is expected to increase the productivity and quality of quail egg. The variables observed consisted of productivity (water intake, feed intake, egg weigh, QDP, egg mass, FCR, mortality) and egg quality (yolk, albumen, shell weight and percentage, egg index, yolk index, albumen index, shell thickness, yolk color, and haugh unit). This study was analyzed using the T test with 2 treatments and 4 replications: T0 = drinking water without any additives and T1 = drinking water with a concentration 10% of chaya leaf infusion. The results showed that chaya leaf infusion had a significant effect (P≤0.05) on quail day production, egg mass, albumen index, and yolk color. Besides that, supplementation chaya leaf infusion significantly reduces (P<0.05) feed convertion ratio. So that the use of 10% chaya leaf infusion in drinking water by giving it 2 times a week can increase the productivity and egg quality of laying quail (Coturnix coturnix japonica) 17-20 weeks old.

Auxin inhibits chlorophyll accumulation through ARF7-IAA14-mediated repression of chlorophyll biosynthesis genes in Arabidopsis.

Auxin is a well-known important phytohormone in plant that plays vital roles in almost every development process throughout plant lifecycle. However, the effect of auxin on the metabolism of chlorophyll, one of the most important pigments involved in the photosynthesis, was intertwined and the underlying mechanism remained to be explored. Here, we found the auxin-defective yuc2 yuc6 double mutant displayed dark-green leaf color with higher chlorophyll content than wildtype, suggesting a negative regulatory role of auxin in chlorophyll biosynthesis. The chloroplast number and structure in mesophyll cells were altered and the photosynthetic efficiency was improved in yuc2 yuc6. In addition, the chlorophyll level was significantly improved during seedling de-etiolation in yuc2 yuc6 mutant, and decreased dramatically under IAA treatment, confirming the inhibitory role of auxin in chlorophyll biosynthesis. The analyses of gene expression in mature leaves and de-etiolation seedlings suggested that auxin suppressed the expression of many chlorophyll biosynthesis genes, especially PROTOCHLOROPHYLLIDE OXIDOREDUCTASE A (PORA) and GENOMES UNCOUPLED 5 (GUN5). Yeast-one-hybrid and luciferase assays demonstrated that the AUXIN RESPONSE FACTOR 2 (ARF2) and ARF7 bind to the promoter of PORA and GUN5 to suppress their expression with the help of INDOLE-3-ACETIC ACID14 (IAA14). Collectively, our research explicitly unraveled the direct inhibitory role of auxin in chlorophyll biosynthesis, and provided new insight into the interplay between auxin signaling and chlorophyll metabolism.

IDENTIFIKASI MORFOLOGI TANAMAN AREN ASAL KABUPATEN LEBAK

Sugar palm is a commodity that has the potential to be developed. Sugar palm is developed to produce various products and raw materials for derivative products. Currently, there is a lot of morphological diversity of sugar palm plants found in the field. Presently, identification of various types of sugar palm morphologically in Banten Province is still limited. Sugar palm in Banten Province is found in various locations, such as in Lebak. This study aimed to determine the characteristics of Aren seedlings originating from Lebak Regency. The hypothesis in this study is that there are several characteristics of palm seedlings originating from Lebak Regency. This research was conducted in August 2019 - November 2019 located in Green House, Cinanggung Village, Serang City, Banten Province. This study uses a descriptive method, through a quantitative approach with data analysis and interpretation, and conclusion. The observation parameters in this study were: Plant Height (cm); Number of leaves per plant (strands); Leaf width (cm); Leaf length (cm); stem diameter (cm); Leaf color. The results showed that Aren from Lebak Regency aged 1 year have an average plant height of 28.1 cm, a pinnate leaf shape and a thick like a palm leaf, with an average number of 1 leaves, an average leaf length of 16.4 cm, and an average leaf width of 6.8 cm, with dark green leaf color. The stem diameter has a strength correlation with plant growth level like as plant height, the higher the plant. The greater the stem diameter obtained in this study is 2.19 cm.

Consumer preference for some genotypes of ornamental chili (Capsicum spp.) population F2

The experiment was conducted to determine the characteristics of ornamental chili plants from several genotypes in the F2 population by consumer desires. This research performed using a single plant method. The planted community consists of all the elders (P) and crossing results. This study uses survey techniques and questionnaires as research aids in obtaining ornamental chili character information that is the public likes. Consumer preference test results (I) against 14 genotypes show that the average consumer most wants TR 23 x TR 25U (1) in some of the characters tested: the leaf color, habitus, and fruit color characters. Genotype TR23 x TR 25U (1) has a dark green leaf color character with a scale of 5 based on the IRRI Leaf Color Chart, a compact habitus, and has two color changes in the fruit, green-red and purple-red. Based on the results of the consumer preference test (II) on four genotypes, it shows that there is no difference in the average value of consumer preferences in the genotypes TR 23B x Ayesha (3), TR 25U, and TR 25 x Ayesha (2) in the characters tested.

Distribution and phenotypic variation in Juglans regia L. growing in Hindu Kush ranges of Pakistan

It has been shown that plant morphology and pomology are shaped by their genotype and respective environmental changes. We hypothesize that climate induces variability in Juglans regia (walnut) landraces growing in the un-explored area of Pakistan. ArcGIS modelling and cartographic functions were performed for the indication of variation in temperature, precipitation, mean diurnal range, humidity and precipitation seasonality. Maxent Modelling techniques were used to determine the most important variables responsible for the current distribution of the species. Among the qualitative traits, Broad elliptic leaf shape and dark green leaf color were dominant traits in all three districts, while Ovate Nut shapes were noted in district Swat and Upper Dir and Broad ovate shapes were recorded in district Lower Dir. For quantitative traits the Pearson correlation revealed that leaf width (LW) showing positive significant correlation with nut volume (NV) (r = 0.24) and nut diameter (ND) (r = 0.199) only in district Swat. Descriptive statistics revealed that nut volume (NV) showed high variation i.e. 32.97% in district Upper Dir & 32.54% in District Lower Dir followed by 10 KW (kernel weight) with 27.26% diversity in district Swat. It was found that, genotypes representing 21.09% nut length (NL) and nut diameter (ND) 10.72% variation while mean value 28.32 and 83.96 respectively with the annual rainfall of 75.15 mm in district Swat, but with gradual increase in rainfall (99.17 mm), genotypes in district Lower Dir contained comparatively smaller nut length (NL) 13.21% and nut diameter (ND) 8.38% variation with mean value 32.93 and 86.38 respectively. Consequently, the genotypes with the smallest nut length (NL) and nut diameter (ND) of 10.71% with the mean value of 30.00 and 7.43% variation with mean value 85.88 respectively were recorded in district Upper Dir where the annual rainfall recorded was 109.75 mm. The regression analysis indicates that rainfall significantly (p ≥ .045 and 0.012) affect the Nut length and Nut diameter with r = −0.99* and r = −1.00*, respectively. It was obvious that, gradual increase in rainfall reduced nut length and nut diameter. The study gives insights in probable effects of environmental variables on the walnut morphology.

Roka (Eruca sativa L.) Yetiştiriciliğinde Katı ve Sıvı Organik Gübre Uygulamalarının Spektral Yansıma Üzerine Etkisi

Bitkilerin spektral yansıma karakteristikleri bitki besin maddesi konsantrasyonları, stres ve diğer faktörlerin etkisi ile vejetasyon periyodu boyunca farklılık göstermektedir. Roka (Eruca sativa L.) gibi yaprağı yenen sebzelerde verimi arttırmak ve tüketicinin tercih ettiği koyu yeşil yaprak rengini kısa sürede sağlayabilmek için yoğun gübreleme yapılmaktadır. Bu çalışmada roka bitkisine artan dozlarda tabandan uygulanan katı ve sıvı organik gübre uygulamalarının, elektromanyetik spektrumun farklı dalga boyu aralığındaki enerji kullanımı üzerine etkileri araştırılmıştır. Çalışma kontrollü sera ortamında tesadüf parselleri deneme desenine göre yürütülmüştür. Denemede bitki yetişme periyodu süresince farklı dozlarda tabandan katı organik gübre (KOG) ve damlamadan sıvı organik gübre (SOG) uygulanmıştır. Bu süreçte elektromanyetik spektrumun 330-1075 nm dalga boyu aralığında el spektroradyometresi ile spektroradyometrik ölçümler gerçekleştirilmiştir. Araştırma sonucunda, her ölçümde uygulamalar ve dönemler arasında istatistiksel olarak farklılıkların olduğu tespit edilmiştir. Katı+sıvı organik gübre uygulamalarının spektral yansıma üzerinde oluşturduğu varyasyonun en fazla ve en az olduğu ölçümler sırasıyla mavi band bölgesinde; 4. ve 8. ölçümler, yeşil band bölgesinde; 5. ve 3. ölçümler, kırmızı band bölgesinde; 2. ve 8. ölçümler, yakın infrared band bölgesinde ise; 2. ve 7. ölçüm dönemlerinde tespit edilmiştir. Bu sonuçlar doğrultusunda varyasyonun en fazla ve en az olduğu ölçüm dönemlerinin bitki stres koşullarının tespit edilmesinde belirleyici olduğu sonucuna ulaşılmıştır.

Comparative profiling of microRNAs and their effects on abiotic stress in wild-type and dark green leaf color mutant plants of Anthurium andraeanum ‘Sonate’

MicroRNAs (miRNAs) are a class of non-coding small RNAs that play important roles in the regulation of gene expression. Although plant miRNAs have been extensively studied in model systems, less is known in other plants with limited genome sequence data, including Anthurium andraeanum. To identify miRNAs and their target genes in A. andraeanum and study their responses to abiotic stresses, we conducted deep-sequencing of two small RNA (sRNA) libraries prepared from young leaves of wild-type (WT) and dark green (dg) leaf color mutant plants of A. andraeanum ‘Sonate’. A total of 53 novel miRNAs were identified, 32 of which have been annotated to 18 miRNA families. 10 putative miRNAs were found to be differentially expressed in WT and dg, among which two miRNAs were significantly up-regulated and eight down-regulated in dg relative to WT. One differentially expressed miRNA, Aa-miR408, was dramatically up-regulated in dg. qRT-PCR analysis and heterologous expression of Aa-miR408 in Arabidopsis under different stress treatments suggest that Aa-miR408 is involved in abiotic stress responses in A. andraeanum. Our results provide a foundation for further dissecting the roles of miRNAs and their targets in regulating abiotic stress tolerance in A. andraeanum.

Photosynthesis of Sago Palm (Metroxylon sagu Rottb.) Seedling at Different Air Temperatures

Photosynthetic activities of the sago palm (Metroxylon sagu Rottb.) were studied to find out its sensitivity to changes in ambient air temperature. The minimum ambient air temperature designed for the experiment was 25–29 °C, while the higher end was 29–33 °C. Several photosynthetic parameters were studied to support our analysis in sago photosynthetic activity, including diurnal leaf gas exchange, assimilation rate vs. CO2 concentration, leaf greenness, leaf chlorophyll content, and photosynthetic rate vs. irradiance. We found that sago palm photosynthetic activity tends to be more sensitive to minimum than to maximum ambient air temperature. The plants exposed to higher air temperatures had dark green leaf color associated with higher rates of diurnal photosynthesis, chlorophyll content, and rubisco limited photosynthetic activity. They also exhibited higher trend in optimum irradiance absorption level. Consequently, maximum light energy dissipation occurred at higher temperatures.

Characterization and categorization of Indian mustard genotypes for agro-morphological traits

A total of sixty genotypes and germplasm lines were evaluated and characterized for 14 quantitative and 8 qualitative traits in Brassica juncea. Observations were recorded on the basis of scores given in the DUS descriptor. Majority of accessions were very late in maturity and medium in flowering. No variability was observed for leaf length and leaf width. On the basis of branches, most of the genotypes were classified under intermediate category. Long main shoot length (31), medium number of siliquae on main shoot (46), medium density on main shoot (52), short siliqua length (51), very tall plant height (38), few numbers of seeds per siliqua (33), medium 1000-seed weight (38), medium seed yield per plant (32) and low oil content (40) were observed in most of the genotypes. For qualitative traits, most of the genotype showed dark green leaf color, sparse hairs, dentation of leaf margin lyrate type, open leaf growth habit, yellow petal color, semi-appressedsiliqua angle with main shoot and intermediate siliqua surface texture. Wide (Yellow, Dull grey, Reddish brown, Brown and Black) diversity has been observed for seed color.

Four new varieties of Begonia from interspecific hybridization Begonia natunaensis C.W.Lin &amp; C.I.Peng × Begonia puspitae Ardi

Siregar HM. 2016. Four new varieties of Begonia from interspecific hybridization Begonia natunaensis C.W.Lin &amp; C.I.Peng × Begonia puspitae Ardi. Biodiversitas 17: 776-782. Increased phenotypic diversity of ornamental plants (e.g. Begonia) can often be achieved by hybridization and selection in the F1 generation. This study aimed to produce new F1 varieties which it was hoped would display improved phenotypic characteristics compared to the contributing parents. The study was conducted in the green house of Bogor Botanic Gardens. Two native species of Indonesia, Begonia natunaensis C.W.Lin &amp; C.I.Peng and B. puspitae Ardi, were used as parent plants. The mature F1 seeds were sown and selections were made among the plants produced. The result of the selection were four new accessions of F1 plants (X1, X3, X10, X22). The selected F1 plants were then propagated vegetatively with leaf cuttings. These were named, described and registered at the Center for Plant Variety Protection (PPVTPP). This resulted in the registration of the following F1 cultivars: X1 named Begonia Blirik which is registered as No. 347/PVHP/2015 and is characterized by purplish peltate leaves with bright whitish green veins, and white flowers; X3 named Begonia Fiandani, registered as No. 348/PVHP/2015 and characterized by dark green leaf color, corrugated leaf surface, and pink flowers; X10 named Begonia Green Peltate, registered as No. 345/PVHP/2015 and characterized by large green peltate leaves, and red flowers; and X22 named Begonia Natunapangean, registered as No. 346/PVHP/2015, and characterized by eccentrically shaped, green basifixed leaves, with ovate shape, and cordate leaf base. Thus the new varieties have been registered in PPVTPP, in accordance with legislation in force. These new varieties are beautiful ornamental Begonia hybrids with exotic leaves, which will be developed as commercial ornamental plants. Keywords: Begonia natunaensis, Begonia puspitae, Begonia Blirik, Begonia Green peltate, Begonia Natunapangean, Begonia Fiandani, interspecific hybridization

Growth and Physiological Response to Nitrogen Deficiency and Re-supply in Leaf-vegetable Sweetpotato (Ipomoea batatas Lam)

Nitrogen (N) is an essential macronutrient limiting plant growth and quality of leaf-vegetable sweetpotato (Ipomoea batatas Lam). The objective of this study was to investigate the effects of N deficiency and re-supply on growth, physiology, and amino acids in sweetpotato. Two leaf-vegetable sweetpotato cultivars, Pushu 53 and Tainong 71, were subjected to three treatments in hydro-culture: 1) N sufficiency, 2) N deficiency, and 3) N deficiency and subsequently with N re-supply. Compared with N sufficiency, N deficiency caused a decrease in vine growth, carotenoid and chlorophyll content (Chlt), root viability, photosynthesis, and nitrate reductase (NR) activity in both cultivars, but to a great extent in Tainong 71. Whereas N deficiency increased root growth and glutamine synthetase (GS) activity in both cultivars, and the increase in ‘Tainong 71’ was more obvious. Re-supply of N recovered the vine growth, root viability, Chlt, photosynthesis, NR, and GS activity, to a greater extent for ‘Pushu 53’ than for ‘Tainong 71’. N deficiency significantly decreased essential amino acids, including lysine, phenylalanince, isoleucine, tryptophane, leucine, and valine contents and nonessential amino acids, consisting of glutamic acid, aspartic acid, glycine, argnine, and proline content in both cultivars. These results indicated that the light leaf color leafy sweetpotato ‘Tainong 71’ is sensitive to the N availability and the dark green leaf color ‘Pushu 53’ is more tolerant to low N, which appear to reflect the differential response of two cultivars to their different adaptability to N availability.

New Varieties of Weigela

Two new varieties of the genus Weigela—Weigela florida 'Royal' and Weigela florida 'Ruby' are described.The two varieties are approximate.However,Weigela florida 'Royal' is taller,1.5-2.0 m height,it is distinguished by its flower color—sharp crystal jade red and dark green leaf color;W.florida'Ruby' is shorter,only 1.0-1.6 m height,it is distinguished by its flower color—Dan purple and golden yellow leaf color.Bothe two new varieties show the characteristics of ornamental specificity,strong resistance,and early and long flowering period.

Annual Bluegrass and Creeping Bentgrass Response to Varying Levels of Iron

Many biotypes of annual bluegrass (Poa annua L.) are found on golf course putting greens. Although normally considered an invasive weed, annual bluegrass can provide as good a putting surface as creeping bentgrass (Agrostis palustris Huds.). The most desirable biotypes of annual bluegrass are primarily vegetative and have a low flowering frequency. Whether the nutritional requirements of annual bluegrass biotypes differ from one another or from creeping bentgrass is unknown. The response of three flowering (FAB, high seedhead production) and three vegetative (VAB, low seedhead production) biotypes of annual bluegrass (AB), and the three parents of `Penncross' creeping bentgrass (CB) to varying levels of iron (Fe) in greenhouse sand culture was investigated. After establishment, clones were grown for 3 weeks and irrigated with a half-strength Hoagland's solution containing 0, 2, 4, 6, and 8 mg·L-1 Fe in citrate-Fe. Shoot and root responses to Fe were similar for the VAB and FAB biotypes. However, VAB had higher color ratings (darker green leaf color) with Fe treatment level at 4 mg·L-1 than did FAB or CB, which required 6 mg·L-1 Fe for acceptable color. Growth of creeping bentgrass was greater than that of annual bluegrass at every Fe level tested. Shoot dry weights of CB increased significantly with Fe treatment level up to 6 mg·L-1. Shoot dry weight of AB increased up to 4 mg·L-1 Fe and then declined at ≥6 mg·L-1. Root growth of CB increased up to 6 mg·L-1 Fe, but then decreased significantly at 8 mg·L-1 Fe. Root growth of AB increased slightly up to 4 mg·L-1 Fe and then declined at 6 and 8 mg·L-1. Shoot tissue concentrations of Fe were similar for AB and CB at each Fe rate tested except at 8 mg·L-1 Fe, where Fe levels in CB were significantly lower. Based on this work, creeping bentgrass and annual bluegrass respond differently to Fe nutrition, but different biotypes of annual bluegrass appear to respond similarly.

Effect of Pesticide-treated Grass Clippings Used as a Mulch on Ornamental Plants

With increasing pressure to reduce disposal of yard waste in landfills, many homeowners are seeking alternative methods for grass clipping disposal. When turf is treated with pesticides, the collected grass clippings become a potential source of injury to susceptible plants that come in contact with the clippings. In this study, grass clippings were collected at 2, 7, and 14 days after pesticide treatment from a turf treated with chlorpyrifos, clopyralid, 2,4-D, flurprimidol, isoxaben, or triclopyr. The clippings were used as a mulch around Lycopersicon esculentum Mill. (tomato), Phaseolus vulgaris L. (bush bean), Petunia ×hybrida Hort. Vilm.-Andr. (petunia), and Impatiens wallerana Hook. f. (impatiens). Beans were planted 4 weeks prior to mulching, whereas the other plants were grown in the greenhouse for 6 weeks and transplanted into the field 2 weeks prior to mulching. Clippings containing residues of clopyralid, 2,4-D, or triclopyr killed tomato, bean, and petunia plants when used 2 days after pesticide treatment (DAPT) and severely injured these same species when mulched 7 and 14 DAPT. Flurprimidol injured tomato, impatiens, and bean plants when present on mulch collected 2, 7, and 14 DAPT, but was not lethal. Flurprimidol slowed plant growth, caused darker green leaf color, and reduced flowering when mulched at 2 DAPT. Isoxaben injured tomato and bean plants when present on mulch used 2, 7, and 14 DAPT but was not lethal. Injury was not as severe in the second year of the study, indicating different environmental stresses and climatic conditions make predicting pesticide injury for all growing seasons difficult; however, grass clippings from a turf treated with herbicides or plant growth regulators should not be used for mulch around sensitive plants for at least 14 DAPT. Chemical names used: 0,0-diethyl O-(3,5,6-trichloro-2-pyridinyl) phosphorothioate (chlorpyrifos); 3,6-dichloro-2-pyridinecarboxylic acid, triethylamine salt (clopyralid); 2,4-dichlorophenoxyacetic acid, dimethylamine salt (2,4-D); α-(1-methylethyl)-α-[4-(trifluromethoxy)phenyl]-5-pyrimidinemethanol (flurprimidol); N-[3-(1-ethyl-1-methylpropyl)-5-isoxazolyl]-2,6-dimethoxybenzamide and isomers (isoxaben); 3,5,6-trichloro-2-pyridinyloxy acetic acid, triethylamine salt (triclopyr).

Influence of Day and Night Temperatures on Sweet Pepper Seedling Development

Sweet pepper (Capsicum annuum `Resistant Giant no. 4') seedlings were grown for 6 weeks in 128-cell plug trays under 16 day/night temperature (DT/NT) regimes from 14 to 26 °C. Seedling stem length, internode length, stem diameter, leaf area, internode and leaf count, plant volume, shoot dry weight (DW), seedling index, and leaf unfolding rate (LUR) were primarily functions of average daily temperature (ADT); i.e., DT and NT had similar effects on each growth or development parameter. Compared to ADT, the difference (DIF, where DIF = DT - NT) between DT and NT had a smaller but still statistically significant effect on stem and internode length, leaf area, plant volume, stem diameter, and seedling index. DIF had no effect on internode and leaf count, shoot DW, and LUR. The root: shoot ratio and leaf reflectance were affected by DT and DIF. Positive DIF (DT higher than NT) caused darker-green leaf color than negative DIF. The node at which the first flower initiated was related to NT. The number of nodes to the first flower on pepper plugs grown at 26 C NT was 1.2 fewer than those of plants grown at 14 °C NT.