Bud Production Research Articles

Physiology of flowering in litchi (Litchi chinensis): A review

Lychee or litchi (Litchi chinensis Sonn.) is most popular fruit of South-East Asia, produces leaf flushes, flowers and fruits on terminals of new growth. The reproductive phase is associated with the ability to alternate between the production of vegetative and reproductive buds. The stress factors like water stress, cold winter are the triggering factors to induce dormancy which promotes flowering. The trees must experience one flush of vegetative growth during summer immediately after harvest and require a minimum number of three flushes for adequate fruit production. The flushes maturing earliest (before the winter period) produce floral shoots, while trees flushes maturing quite late produce vegetative shoots. The stem must take rest for 4 to 6 weeks prior to winter-spring flush for panicle formation in same flush. High leaf N is conducive for frequent flushes of vegetative growth and concentration less than 1.70 percent discourages initiation of vegetative flushes in the fall period. The vegetative flushing just prior to floral induction results in poor or no initiation and often vegetative shoots. The transition from vegetative to floral development is the consequence of changes in the physical and genetical expression in the shoot apex (with high cytokinin concentration). One month before flower bud formation, abscisic acid increases markedly and total cytokinin content increased in the xylem sap reaching maximum during flower bud formation and full bloom. The chlorophyll concentration dependent photosynthesis rate of lychee leaves on younger flushes and adjacent to fruit, is greater than that on shaded older flushes. The available total non structural carbohydrates or starch is found to be accumulated before flower initiation and leaf flushing. Girdling (generally done when post harvest flushes are matured) and spray of paclobutrazol (PBZ) and/or KNO3 induced flowering in China litchi.

Growing practices and the use of potentially harmful chemical additives among a sample of small-scale cannabis growers in three countries

BackgroundWith the growth of legal cannabis markets there has been recognition of the adverse impacts of certain cannabis growing practices, notably, use of harmful chemicals. A major concern has been the use of Plant Growth Regulators (PGRs) which limit plant size and stimulate bud production. These chemicals, many of which have been banned from food crops, have been found unlisted in cannabis growing nutrients sold online or in hydroponic stores. This study describes the cannabis growing practices used by small-scale recreational cannabis growers and specifically their self-reported use of chemicals. MethodsWeb survey data from 1722 current and recent cannabis growers in Australia, Denmark, and the UK, who were asked about their cannabis growing practices, including the use of fertilizers and supplements. ResultsOverall 44% of the sample reported using any chemical fertilizers, supplements or insecticides. Logistic regression indicated that the unique predictor of the use of chemicals was growing hydroponically. ConclusionProblems associated with product labeling and uncertainty regarding product constituents made it difficult for growers and the researchers to determine which products likely contained PGRs or other harmful chemicals. There is a need for further research to analyze constituents of chemical products marketed to cannabis growers.

A transcriptome analysis of two apple (Malus × domestica) cultivars with different flowering abilities reveals a gene network module associated with floral transitions

Young ‘Nagafu No. 2′ apple trees produce fewer flower buds than the trees of other apple cultivars, including ‘Yanfu No. 6′ (i.e., ‘Fuji’ apple tree exhibiting a bud mutation). Thus, we analyzed the flowering characteristics of these two varieties to further characterize apple floral transition. RNA sequencing was used to characterize differentially expressed genes in buds between the two cultivars during floral transition. Differences in several physiological parameters were also analysed. A total of 3,010, 1,139, and 1346 differentially expressed genes were identified at 30, 50, and 70 days after full bloom. These genes combined with the differences in physiological indices indicated that low gibberellic acid levels and high cytokinin levels in ‘Yanfu No. 6′ buds during the floral induction stage increased the production of flower buds. High cytokinin levels inhibited gibberellic acid signaling and promoted floral transition. Additionally, low gibberellic acid levels likely inhibited shoot elongation by impairing DELLA degradation. Meanwhile, relatively high indole-3-acetic acid and cytokinin levels synergistically maintained meristem activities and accelerated bud growth. Moreover, the high sucrose content in ‘Yanfu No. 6′ buds up-regulated the transcription of TREHALOSE 6-PHOSPHATE SYNTHASE and SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE genes, which ultimately promoted floral induction. The data presented herein indicate that floral transition differences between the two analyzed apple cultivars are linked to sugar and cytokinin signaling pathways.

Immediate vs. evolutionary consequences of polyploidy on clonal reproduction in an autopolyploid plant.

Clonal reproduction in polyploids is expected to exceed that in diploids, due to either the immediate direct effects of whole-genome duplication (WGD) or selection during establishment. The timing of polyploidy effects on clonality are largely unknown despite its hypothesized influence on polyploid success. This study tests the direction and timing of divergence in clonal traits in diploid and polyploid Chamerion angustifolium. Root bud production and biomass allocation patterns were compared between diploids and synthesized tetraploids (neotetraploids), and between neotetraploids and naturally occurring tetraploids grown in a common environment. Neotetraploids produced more root buds and fewer sexual structures than diploids and natural tetraploids; diploids and natural tetraploids had similar root bud numbers and sexual investment. The root bud:inflorescence biomass ratio was 71 % higher in neotetraploids than in natural tetraploids. Root bud location suggests that ramet density in neotetraploid genets could be higher than in diploid genets. WGD immediately increases investment in asexual vs. sexual reproduction in C. angustifolium, potentially promoting within-cytotype mating and establishment for neopolyploids. However, evolutionary change after the polyploidization event negates the direct effects of WGD. Natural polyploids and diploids have similar root bud production and biomass allocation patterns, probably resulting from habitat- and ploidy-mediated selection on polyploids to become more like diploids. These results highlight the value of studying the effects of polyploidization in young vs. established polyploids.

TAKSASI PRODUKSI MATA TUNAS SEBAGAI BENIH TEBU (SACHARRUM OFFICINARUM L.) DENGAN PENDEKATAN ANALISA REGRESI

<p>One of the problems encountered in the development of sugarcane (Sacharrum officinarum L.) includes the availability of sugarcane seed both in quality and quantity. Evaluation of bud sett planting method in seed production was required in order to achieve the expected results. The study was conducted at the experiment station Muktiharjo, Central Java in 2012 using PSJT 941 varieties. Treatments applied were the different number of buds on bud sett which were at 3 levels, 1 bud, 2 buds or 3 buds. Research was arranged in a randomized complete block design (RCBD) with 5 replications. Observations were conducted on germination, tillering, plant height, number of stems, number of suckers and number of buds. The data obtained were analyzed with ANOVA and further tested using the Duncan test. Production assessment modeling approach was performed by a regression analysis. Calculation of stem number on 2 buds showed the highest with 9.6 stems/m, 9.2 buds/stem and with the sucker numbers lowest at 0.38 suckers/m. The highest production buds was obtained at planting 2 buds with 847,848.06 buds/ha which can be used as 8.83 ha for the milled sugarcane plantation. Assessment of bud production per hectare could use equation Y = 159655,48.e0,171.X with the independent variable of stem numbers per meter with a correlation coefficient of 0,9007 and a standard error of 1,0699.</p>

Growth and carbon balance are differently regulated by tree and shoot fruiting contexts: an integrative study on apple genotypes with contrasted bearing patterns.

In plants, carbon source-sink relationships are assumed to affect their reproductive effort. In fruit trees, carbon source-sink relationships are likely to be involved in their fruiting behavior. In apple, a large variability in fruiting behaviors exists, from regular to biennial, which has been related to the within-tree synchronization vs desynchronization of floral induction in buds. In this study, we analyzed if carbon assimilation, availability and fluxes as well as shoot growth differ in apple genotypes with contrasted behaviors. Another aim was to determine the scale of plant organization at which growth and carbon balance are regulated. The study was carried out on 16 genotypes belonging to three classes: (i) biennial, (ii) regular with a high production of floral buds every year and (iii) regular, displaying desynchronized bud fates in each year. Three shoot categories, vegetative and reproductive shoots with or without fruits, were included. This study shows that shoot growth and carbon balance are differentially regulated by tree and shoot fruiting contexts. Shoot growth was determined by the shoot fruiting context, or by the type of shoot itself, since vegetative shoots were always longer than reproductive shoots whatever the tree crop load. Leaf photosynthesis depended on the tree crop load only, irrespective of the shoot category or the genotypic class. Starch content was also strongly affected by the tree crop load with some adjustments of the carbon balance among shoots since starch content was lower, at least at some dates, in shoots with fruits compared with the shoots without fruits within the same trees. Finally, the genotypic differences in terms of shoot carbon balance partly matched with genotypic bearing patterns. Nevertheless, carbon content in buds and the role of gibberellins produced by seeds as well as the distances at which they could affect floral induction should be further analyzed.

EFFECT OF FIRE ON FLOWERING AND FRUITING OF ANACARDIUM HUMILE (ANACARDIACEAE) IN CERRADO STRICTO SENSU

ABSTRACT Knowledge about the effects of fire on sexual reproduction of Cerrado woody species is fundamental for elaborating public policies and management plans for its conservation. The present study evaluated the effect of a controlled burning on flowering and fruiting of Anacardium humile in an Cerrado stricto sensu environment, in Cavalcante, GO. An area with no fire records for five years was submitted to controlled burning in May 2016, used as the experimental area and its adjacent areas protected from fire as control area. In each area, 16 reproductive individuals were selected and their production of floral buds, flowers and fruits, followed up for 17 months. In 2016 the production of reproductive structures was higher in the control area, since the majority of individuals of the burned area invested in the recovery of vegetative structures (branches) damaged by fire. Only three individuals flowered in the burned area in 2016 and presented greater effort in the production of buds and flowers per panicle than the individuals in the control area, however, the fruit set was equal between the areas. One year after fire, the production of reproductive structures became equal between areas. The control area presented higher fruit production in 2017 in comparison to 2016, indicating a variable pattern in annual fruit production. The impact of fire on the reproductive structures of A. humile is greater in the same year of fire and its reproductive potential can be normalized in the subsequent year.

Ramet versus sporocarp production in the aquatic fern Salvinia auriculata (Salviniaceae): the role of shading

Aquatic plants exposed to environmental changes exhibit plastic responses, resulting in functional adjustments to reduce stress effects. Lack of light can limit plant development and can affect biomass allocation and reproduction, stressing plants and sometimes halting their growth. Shading techniques have been used to control the excessive growth of weed plants, such as the aquatic fern Salvinia auriculata Aublet that can form dense mats on the water surface, causing problems in water use. We used shading nets in a greenhouse experiment to evaluate the effect of shade on the biomass of S. auriculata, and to determine if the fern changes its allocation of biomass to sexual (sporocarps) or asexual (buds) reproduction under different shade levels (full-sun control, 35% shade, and 70% shade). Under shade conditions, ramet biomass decreased and no sporocarps were produced, although the number of buds increased. Production of structures for sexual reproduction incurs a high energy cost, so S. auriculata invested in bud production (clonal reproduction). The differing energy requirements resulted in a significant trade-off between bud and sporocarp production. In conclusion, our study indicated that shading is not an efficient control technique for S. auriculata since it did not affect the clonal reproduction, a strategy that accelerates colonisation and facilitates rapid spread.

Study the effect of Ca(NO3)24H2O on root initiation in notch no. 3, 4, 5, 6 of the 5th leaf of Bryophyllum.

The role of ages of leaf, the position of notch on the leaf, supplemented nutrients and growth regulators etc. on the initiation of adventitious roots and their subsequent growth in excised Bryophyllum leaves was investigated, notches of Bryophyllum leaf was the most important site for the initiation of adventitious roots. Adventitious roots were initiated from the notches when isolated leaves were placed on soil or sand sprayed with water frequently. The number of notches in a Bryophyllum leaf ranged between six to thirty-six but adventitious roots didn't develop equally on all the notches present. It might so happen that the root hormones present at the notches responsible for root initiation were not present in the notches in suitable concentrations other physiological conditions prevailing at the notches might also be responsible for root initiation. Depending on the interesting behaviour of Bryophyllum leaves, a study on the physiology of initiation of root and subsequent growth of those roots in 5th leaf particularly 3rd, 4th, 5th and 6th notches in presence of externally supplied Chemicals like Ca (NO3)2 4H2O carried out. As various factors played major role in production of adventitious roots and buds in the notches, a preliminary screening was done to ascertain the most suitable leaf in regard to root initiation number of root produced per notch, length of each root time taken for root initiation, in the notches. Further it was thought essential to select the most suitable notch for early initiation of root production of maximum number of roots and the maximum growth of roots. During the course of the research, it was found. That in the young Bryophyllum plants the 5th leaf (counted from the apex toward the base, leaving the young terminal bud) showed early rooting, maximum number of roots and longest roots. Then could possibly be attributed to the most capable leaf.

A new scaly tree fern (Cyathea: Cyatheaceae) from Colombia

Based on recent collections, we describe a new species of scaly tree fern, Cyathea giraldoi, from northern Colombia and discuss its ecology. The new species differs from putative close relatives by a character combination including a small size, often decumbent trunk, strongly arching fronds with drooping tips, nearly triangular lamina, thick scurf of matted arachnoid squamules, and frequent production of adventitious buds.

Massive and Reproducible Production of Liver Buds Entirely from Human Pluripotent Stem Cells

Organoid technology provides a revolutionary paradigm toward therapy but has yet to be applied in humans, mainly because of reproducibility and scalability challenges. Here, we overcome these limitations by evolving a scalable organ bud production platform entirely from human induced pluripotent stem cells (iPSC). By conducting massive "reverse" screen experiments, we identified three progenitor populations that can effectively generate liver buds in a highly reproducible manner: hepatic endoderm, endothelium, and septum mesenchyme. Furthermore, we achieved human scalability by developing an omni-well-array culture platform for mass producing homogeneous and miniaturized liver buds on a clinically relevant large scale (>108). Vascularized and functional liver tissues generated entirely from iPSCs significantly improved subsequent hepatic functionalization potentiated by stage-matched developmental progenitor interactions, enabling functional rescue against acute liver failure via transplantation. Overall, our study provides a stringent manufacturing platform for multicellular organoid supply, thus facilitating clinical and pharmaceutical applications especially for the treatment of liver diseases through multi-industrial collaborations.

Effects of an accidental dry-season fire on the reproductive phenology of two Neotropical savanna shrubs.

Fire is a recurrent disturbance in savanna vegetation and savanna species are adapted to it. Even so, fire may affect various aspects of plant ecology, including phenology. We studied the effects of a spatially heterogeneous fire on the reproductive phenology of two dominant woody plant species, Miconia albicans (Melastomataceae) and Schefflera vinosa (Araliaceae), in a savanna area in South-eastern Brazil. The study site was partially burnt by a dry-season accidental fire in August 2006, and we monitored the phenolology of 30 burnt and 30 unburnt individuals of each species between September 2007 and September 2008. We used restricted randomizations to assess phenological differences between the burnt and unburnt individuals. Fire had negative effects on the phenology of M. albicans, with a smaller production of reproductive structures in general and of floral buds, total fruits, and ripe fruits in burnt plants. All unburnt but only 16% of the burnt M. albicans plants produced ripe fruits during the study. Fire effects on S. vinosa were smaller, but there was a greater production of floral buds and fruits (but not ripe fruits) by burnt plants; approximately 90% of the individuals of S. vinosa produced ripe fruits during the study, regardless of having been burnt or not. The differences between the two species may be related to S. vinosa's faster growth and absence from the seed bank at the study site, whereas M. albicans grows more slowly and is dominant in the seed bank.

Influence of vernalization and bulb size on the production of lily cut flowers and lily bulbs

Exposure of bulbs to cold, a physiological phenomenon called vernalization, and bulb size are important factors in the production of lily bulbs and flowers. This study aimed to verify the influence of vernalization of bulbs on flowering cut lily plants, as well as the impact of size and shape of harvest on the production and quality of flowers and bulbs. In turn, the way the stems of the plants used for cut-flower production are cropped is of higher importance for the production of new flower bulbs. In this sense, the experiment was conducted in Viçosa, MG, in a greenhouse in a randomized block design, in split splot scheme with three replications, in which the vernalization periods (25, 35 and 45 days at 4 ± 1 C) constituted the plots; bulb sizes (diameters of 3.2-3.8 cm; 2.5-3.2 cm 1.9- and 2.5 cm), subplots and ways to harvest (full harvest of the stem at the required length for the commercial harvest of the flower, commercial stem harvest at the commercial length, maintaining 10cm of stem in the soil; removal of the floral buds as soon as their appearance is observed and harvest at the end of the season), the sub subplots. The bulbs were planted in beds, with 15 x 20 cm spacing. It was evaluated the number of plants that flowered and the number of flowers, the length and the diameter of the floral buds, fresh and dry weights, diameter and plant height as well as number, perimeter and amount of fresh and dry bulbs. There was a decrease in the plant height with the increase of the vernalization period and a reduction of the diameter of the planted bulbs, as well as of the number and the fresh and dry weights of the produced buds. The production of flowers and buds in number, size and weight was directly proportional to the size of the planted bulbs, while the form of harvest with removal of flower buds increased the number, the perimeter and the fresh and dry weights of the buds. Bulbs with diameter between 3.2 - 3.8 cm, stored for 25 days in cold chamber enable greater production of flowers and the highest stem height, factors that favor the increase in market value.

Influence of vernalization and bulb size on the production of lily cut flowers and lily bulbs

Exposure of bulbs to cold, a physiological phenomenon called vernalization, and bulb size are important factors in the production of lily bulbs and flowers. This study aimed to verify the influence of vernalization of bulbs on flowering cut lily plants, as well as the impact of size and shape of harvest on the production and quality of flowers and bulbs. In turn, the way the stems of the plants used for cut-flower production are cropped is of higher importance for the production of new flower bulbs. In this sense, the experiment was conducted in Viçosa, MG, in a greenhouse in a randomized block design, in split splot scheme with three replications, in which the vernalization periods (25, 35 and 45 days at 4 ± 1 C) constituted the plots; bulb sizes (diameters of 3.2-3.8 cm; 2.5-3.2 cm 1.9- and 2.5 cm), subplots and ways to harvest (full harvest of the stem at the required length for the commercial harvest of the flower, commercial stem harvest at the commercial length, maintaining 10cm of stem in the soil; removal of the floral buds as soon as their appearance is observed and harvest at the end of the season), the sub subplots. The bulbs were planted in beds, with 15 x 20 cm spacing. It was evaluated the number of plants that flowered and the number of flowers, the length and the diameter of the floral buds, fresh and dry weights, diameter and plant height as well as number, perimeter and amount of fresh and dry bulbs. There was a decrease in the plant height with the increase of the vernalization period and a reduction of the diameter of the planted bulbs, as well as of the number and the fresh and dry weights of the produced buds. The production of flowers and buds in number, size and weight was directly proportional to the size of the planted bulbs, while the form of harvest with removal of flower buds increased the number, the perimeter and the fresh and dry weights of the buds. Bulbs with diameter between 3.2 - 3.8 cm, stored for 25 days in cold chamber enable greater production of flowers and the highest stem height, factors that favor the increase in market value.

Reproductive ecology of the threatened "star cactus" Astrophytum ornatum (Cactaceae): a strategy of continuous reproduction with low success

Background. There are no previous studies on the reproductive biology of the endemic and endangered cactus species Astrophytum ornatum. 
 Questions. Is flowering continuous or episodic? What are the breeding and mating systems and what floral visitors are associated? and Does the reproductive success change over time?
 Study species. Astrophytum ornatum (Cactaceae).
 Study site and years of study. Observations from 2010 to 2011, in the highest density population of A. ornatum in Metztitlán Canyon (Hgo.).
 Methods. Monthly surveys and monitoring of reproductive structures. Tracking flowers in anthesis. Controlled pollinations to determine the mating system and determination of the Outcrossing Index (OCI), the pollen /ovule ratio and breeding system.
 Results. Astrophytum ornatum produced flower buds throughout the year, but 89.2% of them were aborted. Four events of ephemeral flowering population were presented per year. The species is self-incompatible and controlled pollinations indicated pollinator limitation of several bee species. The OCI indicates that the species is facultative xenogamy, and pollen/ovule ratio indicates obligate xenogamy. On average there were 54 seeds/fruit and individuals produced 4 fruits/year.
 Conclusions. The continuous production of buds had never been reported phenomenon for cacti. Intrapopulation bloom is one of the shortest recorded for the family and it produces high floral synchrony. The low number of seeds / fruit and flowers / individual, coupled with the narrow niche breadth of species and various anthropogenic factors place Astrophytum ornatum as a susceptible species to be extinct.

Branch bending affected floral bud development and nutrient accumulation in shoot terminals of ‘Fuji’ and ‘Gala’ apples

Branch bending has been practiced for decades in China to induce flower buds in ‘Fuji’ apple. However, the optimum bending angle is yet to be elucidated. The main objectives of this study were to compare the effect of branch bending angles (70°, 90° and 110°) on the flowering and nutrient accumulation of 1-year-old shoots of ‘Fuji’ and ‘Gala’ apples and to determine the optimum branch bending angle for each cultivar. In both cultivars, the production of spurs and terminal flower buds, and the total sugar concentration and the carbon-to-nitrogen (C/N) ratio in the shoot terminals increased, whereas the N concentration decreased with increasing bending angles. The nutrient concentration was significantly higher in spurs than in medium and long shoots. The distinction between the changing patterns of C and N concentrations in the bent shoots during the growing season in our study suggested the competition of these two nutrients caused by vegetative and reproductive growth at different growing times. In ‘Fuji’ apple, the proportion of flowering buds appeared to increase more rapidly with the increase of bending angle from 70° to 110° than that in ‘Gala’ apple, and particularly a higher proportion of spurs was observed on ‘Fuji’ branches bent at a larger angle. The increase in the total sugar concentration and the C/N ratio in the shoot terminals of the bent branches might be involved in inducing floral buds after bending. The optimum bending angle was about 90° for ‘Gala’ apple and 110° for ‘Fuji’ apple, respectively. Bending could help farmers to reduce the severity of biennial fruiting in ‘Fuji’ apple.

Studies on the effect of media on sucker production of banana cv. POOVAN

In vivo macropropagation is an alternative simple and cheap technique for banana multiplication. The experiment was conducted in Completely Randomized Design with 13 treatments in three replications. The treatments consisted of three growing media (FYM, Rice hull, Sawdust), two biofertilizers ( Azospirillum and VAM) with sand alone as control. Observations on the production of primary, secondary and tertiary buds was recorded. The results of the study revealed that use of FYM + VAM (T 7 ) as growing media resulted in increasing the primary, secondary and tertiary bud regeneration. The time taken for emergence of primary, secondary and tertiary buds was also earlier in the treatment T 7 (FYM + VAM).

Phenology of perennial, native grass, belowground axillary buds in the northern mixed-grass prairie.

Vegetative reproduction from belowground bud banks is the primary driver of grassland systems. Despite the importance of bud banks, the timing of recruitment and the crucial link between formation and maintenance is unknown. We assessed patterns of belowground bud development, dormancy, and mortality associated with three perennial native grasses in the northern Great Plains. Temperature and soil moisture were measured below the soil surface to determine relationships with belowground bud development. Blue grama (Bouteloua gracilis) generated more buds over winter that remained dormant; whereas, C3 species needle-and-thread (Hesperostipa comata) and western wheatgrass (Pascopyrum smithii), maintained limited dormant buds throughout winter. Soil temperature was a good predictor for C4 species bud production; whereas, soil moisture was a reliable predictor for C3 buds. Distinct differences existed between C4 species blue grama and C3 species needle-and-thread, whereas C3 species western wheatgrass (Pascopyrum smithii) was intermediate, indicating there is likely a species-specific continuum between the C3 and C4 extremes rather than a stark difference. The ability to predict belowground bud development is a novel insight to native perennial grasses. Native grass species' strategies and adaptability regarding belowground bud bank size and bud phenology are important factors optimizing tiller recruitment given the variable growing conditions. Patterns of bud dormancy and development will provide insight to the underlying mechanisms by which management practices and fluctuations in precipitation amount and growing season length can alter mixed-grass prairie plant community dynamics.

Macro-propagation of dwarf Cavendish banana

Effect of growing media on macro-propagation of dwarf Cavendish banana was studied in an experiment conducted during 2012 to 2014 at the Farm, Department of Horticulture, Assam Agricultural University, Jorhat, Assam. The experiment was laid out in completely randomized design with three replications under ploy house condition. Evaluation of macro-propagation practice using sawdust as initiation media, supplemented with various biofertilizers resulted in highest number of uniform sized tertiary bud production when the decorticated corm cavity was poured with 40 ppm BAP (4 ml) and the media was supplemented with Bacillus subtilis alone and along with VAM. This treatment also performed better regarding shortest time requirement for production of first primary bud and total number of tertiary suckers, and other vegetative growth characters.

Weather parameters vulnerability on tea production in north western Himalaya, India

The study assessed the sensitivity of weather parameters with respect to total green leaf and two leaves and bud (T & B) productivity of tea crop {Camellia sinensis (L.) Kuntze}. The maximum temperature ranging from 20.0 to 29.0 oC during March, May, August and September showed positive relationship with values ranging from 0.26 to 3.38 and 0.22 to 3.22 for green leaf and T & B yield, respectively. Similarly, minimum temperature ranging from 9.1 to 20.0 oC during March and July to October found positive 0.001 to 2.93 and 0.28 to 2.91 for green leaf and T & B productivity, respectively. The mean monthly rainfall amounting 52.7 to 664.7 mm during March, May, July to October and 52.7 to 488.4 mm during June, July, September and October also showed positive sensitivity with values ranging from 0.03 to 0.33 and 0.007 to 0.35 for green leaf and T & B yield, respectively. The relative humidity ranging between 41.2 to 77.3% during April to May for green leaf yield (0.32 to 1.71) and during April to May and October for two leaf and bud yield (0.00 to 1.70) showed positive relationship. So, maximum and minimum temperature between 20.0 to 29.0 oC and 9.1 to 20.0 oC, respectively with rainfall of 52.7 to 488.4 mm and relative humidity 41.2 to 77.3% are the most beneficial weather parameters for tea cultivation at Palampur conditions.