Leaf of the middle or middle third of the new spur on the tree periphery, with or without fruit, between January 15th and the end of February (south hemisphere). 在每年7月15日至8月底，有果實或沒有果實的外圍新枝條中部或中部三分之一處取剛成熟的葉片。
Leaf of the middle or middle third of the new spur on the tree periphery, with or without fruit, between January 15th and the end of February (south hemisphere).
Boron is an essential micronutrient to plants and is involved in functions such as meristematic growth and cellular differentiation, maturation, division and elongation. Many species vary in their requirements for boron and, usually, there is a narrow range between adequate and toxic levels of boron.硼是植物必需的微量營養素，參與分生組織生長和細胞分化、成熟、分裂和伸長等功能。許多物種對硼的需求量各不相同，通常，硼的充足水平和毒性水平之間的范圍很窄。
摘要：硼是一種重要的植物微量營養元素，主要以硼酸的形式通過根系吸收。其在植物代謝中的重要作用涉及具有順式二醇基團分子的穩定。該元素涉及細胞壁和膜的結構和功能；因此，它參與許多離子、代謝物和激素轉運反應。硼在缺乏和毒性之間的范圍極窄，硼供應不足會對農業植物的產量產生不利影響。缺硼問題可以通過施肥來解決，而土壤硼毒性可以通過各種方式來改善；然而，這些方法成本高、耗時長，而且往往會產生暫時的效果。植物物種以及物種內的基因型在硼需求方面存在顯著差異；因此，土壤可利用的硼對一種作物缺乏，可能會對另一種作物產生毒性影響。關于硼利用效率和毒性耐受性的廣泛記錄的種內遺傳變異性，加上硼的生理學和遺傳學知識，應引導開發高效和耐受的品種，這可能是硼供應不足或過量問題的長期可持續解決方案。
Abstract: Boron is an essential plant micronutrient taken up via the roots mostly in the form of boric acid. Its important role in plant metabolism involves the stabilization of molecules with cis-diol groups. The element is involved in the cell wall and membrane structure and functioning; therefore, it participates in numerous ion, metabolite, and hormone transport reactions. Boron has an extremely narrow range between deficiency and toxicity, and inadequate boron supply exhibits a detrimental effect on the yield of agricultural plants. The deficiency problem can be solved by fertilization, whereas soil boron toxicity can be ameliorated using various procedures; however, these approaches are costly and time-consuming, and they often show temporary effects. Plant species, as well as the genotypes within the species, dramatically differ in terms of boron requirements; thus, the available soil boron which is deficient for one crop may exhibit toxic effects on another. The widely documented intraspecies genetic variability regarding boron utilization efficiency and toxicity tolerance, together with the knowledge of the physiology and genetics of boron, should result in the development of efficient and tolerant varieties that may represent a long-term sustainable solution for the problem of inadequate or excess boron supply.
雖然硼是一種必需的植物營養元素，但過量會產生毒性。由于井水中的過量硼不存在補救措施，因此應在景觀中種植耐硼植物。“不幸的是，你無法對井水采取任何措施來降低其硼含量，因此選擇耐硼植物是明智的選擇。”
Although boron is an essential plant nutrient, excessive amounts can become toxic. Since no remedies exist for excess boron in well water, stick to boron-tolerant plants in the landscape.“Unfortunately, there is nothing you can do to your well water to reduce its level of boron, so selecting boron-tolerant plants is a wise direction to take.”
硼（B）的毒性最初出現在較低、較老的葉子上。硼中毒的早期癥狀表現為下部葉片起皺和葉緣脈間失綠。起皺最有可能是由于當B的毒性水平存在時，細胞缺乏膨壓引起的。這種褶皺會在葉片表面形成，導致葉片變形。隨著時間的推移，脈間褪綠將向內移動，并在大部分葉片上發展。當供應過量的B時，細胞會迅速死亡，導致壞死斑點。隨著癥狀的發展，褪綠和壞死會在植株上發展到其他葉片。
鎂是一種營養元素，能夠在植物新舊葉片之間移動的礦物質。植物缺鎂會迅速發展，導致下部葉片的鎂流失。鎂是最重要的生長元素之一，因為它位于組織內葉綠素分子的中心。這意味著，如果缺鎂，葉綠素缺乏會導致植物生長發育不良。
鎂是一種高移動的元素，對植物生長發育至關重要。它在土壤中的存在取決于幾個因素：巖石材質、氣象學程度、當地氣候以及特定的耕作制度和做法，如作物類型、耕作強度和作物輪作以及施用方法。因此，鎂的含量可能因土壤類型的不同而有很大差異。在熱帶和砂質土壤中，預計鎂含量較低，而沼澤、泥炭沼澤、鹽漬土附近的土壤，以及通常粘土含量較高的土壤，鎂含量較高。
